JRZ RS Two Touring/Sport Track Review

[tomtang]

Next chapter of my blog is now up! http://www.jrzsuspension.com/betty-u...even-more.html

Happy New Year, folks! =)

[jetbill]

Originally Posted by tomtang

Next chapter of my blog is now up! http://www.jrzsuspension.com/betty-u...even-more.html

Happy New Year, folks! =)

Tom, great review- thanks.
Would you mind posting your alignment settings and shock settings ?

Thanks.

[tomtang]

Sure thing.

Alignment:

Front camber: -3.0 degrees
Rear camber: -2.0 degrees
Front toe: 0
Front caster: OEM
Rear toe: Total toe in 1/16"

Shocks:

Front compression: +6
Front rebound: +7

Rear compression: +4
Rear rebound: +9

Keep in mind, YMMV with this setup as a lot of it is driver preference and also specific to the Nexen tires that I'm running. But I am curious as to what people think. If you do try it, let me know. Thanks.

[Jomnhta]

Interested in how you achieve that rear camber and toe, purely by toe link kit?

[x.shell]

Originally Posted by Jomnhta

Interested in how you achieve that rear camber and toe, purely by toe link kit?

It might be possible to get 1/16 toe in with -2.0 degrees of camber. But I'd be surprised if the stock toe link wasn't swapped out.

[x.shell]

Originally Posted by tomtang

Sure thing.

Alignment:

Front camber: -3.0 degrees
Rear camber: -2.0 degrees
Front toe: 0
Front caster: OEM
Rear toe: Total toe in 1/16"

Shocks:

Front compression: +6
Front rebound: +7

Rear compression: +4
Rear rebound: +9

Keep in mind, YMMV with this setup as a lot of it is driver preference and also specific to the Nexen tires that I'm running. But I am curious as to what people think. If you do try it, let me know. Thanks.

Hey Tom. Did you need to revalve the dampers when you went up to 700/900. Those rates seem perfect for technical tracks but sounds like it would be rough on the street.

[tomtang]

Let me try to answer all of the questions here:

1. Yes, the toe link kit is from Fall Line, which is how I was able to get the rear settings to my liking.
2. Valving did not need to change with the slight increase in spring rate, the dampers can handle these stiffer springs just fine.
3. The info that I gave above is my track setup. I run a less aggressive setup on the street.

[tomtang]

Just installed revised/upgraded RS Two front shocks for the F80: http://www.jrzsuspension.com/new-shocks-for-betty.html

Track test data, feedback, and video at Laguna Seca coming soon! =)

[M4 CSL]

Originally Posted by exo-shell

Hey Tom. Did you need to revalve the dampers when you went up to 700/900. Those rates seem perfect for technical tracks but sounds like it would be rough on the street.

That is very similar spring rate to what my KW CS will be.

To be precise, mine are 110 N/mm Fr and 180 N/mm Rear.

Which I believe comes out at 628 Fr and 1,028 Rear.

So pretty close to your 700 / 900.

KW CS already comes with spherical and has the camber plates.

Hoping Install this Friday, but at Latest next week.

[tomtang]

Sweet. Look forward to hearing about how you like that setup! KW CS are great shocks too.

[bracer]

Just purchased a set of JRZ RS2's. How did you arrive at the 700/900 spring rates?

[x.shell]

Originally Posted by tomtang

Just installed revised/upgraded RS Two front shocks for the F80: http://www.jrzsuspension.com/new-shocks-for-betty.html

Track test data, feedback, and video at Laguna Seca coming soon! =)

Good stuff. I'm looking forward to reading about your impressions on the old vs new shocks.

Also, what spring rates do you use on the street?

[M4 CSL]

Originally Posted by blackey

Just purchased a set of JRZ RS2's. How did you arrive at the 700/900 spring rates?

OEM 185 lb/ft Front, 575 lb/ft Rear
OEM CP 198 lbs/ft Front, 685 lbs/ft Rear

M4 GTS 400 lbs/ft Front, 600 lbs/ft Rear

All of These are comfortable street cars.

The F82 is Seriously under sprung. The M4 GTS does not handle well. No one likes them in stock trim.

They Doubled the front spring rate and barely changed the rear.
Ohlins was one of the first to realise the rear is seriously under sprung.

They went 500 Fr? and 1,300 rear.

I tripled the front and went just over 600. And basically just under doubled the rear at just over 1,000. This is the new Stronger recommendation from KW.

If the ratio is .6 for the rear, (Being separated from shock) then .6 x 1,000 = 600.

So in effect isn't that balanced having 600 Coilover front and 1,000 split at rear?

Just thought that was interesting. Don't know if that's how it really works or not.

Either way 700 - 900 would be a nice improvement.

[x.shell]

Originally Posted by M4 CSL

OEM 185 lb/ft Front, 575 lb/ft Rear
OEM CP 198 lbs/ft Front, 685 lbs/ft Rear

M4 GTS 400 lbs/ft Front, 600 lbs/ft Rear

All of These are comfortable street cars.

The F82 is Seriously under sprung. The M4 GTS does not handle well. No one likes them in stock trim.

They Doubled the front spring rate and barely changed the rear.
Ohlins was one of the first to realise the rear is seriously under sprung.

They went 500 Fr? and 1,300 rear.

I tripled the front and went just over 600. And basically just under doubled the rear at just over 1,000. This is the new Stronger recommendation from KW.

If the ratio is .6 for the rear, (Being separated from shock) then .6 x 1,000 = 600.

So in effect isn't that balanced having 600 Coilover front and 1,000 split at rear?

Just thought that was interesting. Don't know if that's how it really works or not.

Either way 700 - 900 would be a nice improvement.

I know you're really excited about your "stiffer" version of the KW Clubsport. But the spring rates you suggest, and also ordered for your KW CS, will be absolutely jarring for most people on the street. And Ohlins is NOT get it right with their initial Road & Track coilover. The rear spring was so stiff that there was practically no give in the suspension travel; you might as well put a cinder block in there. The result was an absolute lack of height adjustability. If you lowered it too much, the spring would be loose on the perch at full droop and could even pop out of the perch. The result was that you had to keep the ride height really high to compensate. They corrected this on their 2nd offering of the RT kit.

There is a place for stiffer springs and dampers. They will do well on a track. That being said, I'm in the camp that believes BMW got the suspension tuning right on the OEM car. Any modifications you make to it after that will be more about honing in the suspension to your specific needs/desires depending on how you use it.

I would be absolutely miserable with your spring rates daily driving in Los Angeles.

[M4 CSL]

Originally Posted by exo-shell

I know you're really excited about your "stiffer" version of the KW Clubsport. But the spring rates you suggest, and also ordered for your KW CS, will be absolutely jarring for most people on the street. And Ohlins is NOT get it right with their initial Road & Track coilover. The rear spring was so stiff that there was practically no give in the suspension travel; you might as well put a cinder block in there. The result was an absolute lack of height adjustability. If you lowered it too much, the spring would be loose on the perch at full droop and could even pop out of the perch. The result was that you had to keep the ride height really high to compensate. They corrected this on their 2nd offering of the RT kit.

There is a place for stiffer springs and dampers. They will do well on a track. That being said, I'm in the camp that believes BMW got the suspension tuning right on the OEM car. Any modifications you make to it after that will be more about honing in the suspension to your specific needs/desires depending on how you use it.

I would be absolutely miserable with your spring rates daily driving in Los Angeles.

You make some excellent points. People lower their car too much. I doubt I will lower my car anymore than 5 mm, 10 at maximum. The stock car is almost low enough.
This point is lost on many people. I'm glad you made it. Too many young folk go for the slammed look. I was young once too. I did it and hated it. Scraping on everything. And really the suspension can't work as designed.
I am not doing coilovers to lower the car.....I want awesome handling. Pure performance. By not lowering the car, it will allow the suspension to work as intended. I am fine with a firm ride.

(And Yes I am very excited about my stiffer spring rates. I am very competitive.)

A friend of mine has the ohlins, and he daily drives it, and says there isn't that much different to what it was in Sport +. I will be racing him at the track. So we shall learn. I Haven't driven his car yet, but I will very soon.

He is happy with the 1,300 Spring rate. So I totally agree, that suspension is very personal. Each to there own. For me, I get in a firm car, and I can think, wow this is stiff. 5 Mins later, I think , this is fine. So I tend to adapt to stiff suspension rather quickly. I bet for the first 5 minutes, I will think OMG what have I done. Then I will rip through some corners and go, Yeah Baby!

We do a fair amount of Skid pan, drifting on figure "B" track, with diesel and water. As well as cars and coffee, and Roll Racing. But what I really want to set the car up for is, mountain runs. I live in a huge country, with a very small population. So nice twisty, deserted mountain roads. The country is far to vast to police fully. : )

I fitted the Dinan Toe links. I love them. No noise. I expected no real difference, but was really surprised how much they settled the rear already. I am loving the car again. I ordered the SPL adjustable rear sway bar end links, and the Eccentric delete kit. (Will stop toe adjustment from sliping. And the Rear end link for when I upgrade the Anti Roll Bars. Dinan comes with the front one, So I bought a rear one from SPL.

[tomtang]

Originally Posted by exo-shell

Good stuff. I'm looking forward to reading about your impressions on the old vs new shocks.

Also, what spring rates do you use on the street?

Same. Too lazy to change.

Originally Posted by blackey

Just purchased a set of JRZ RS2's. How did you arrive at the 700/900 spring rates?

Through discussion with the engineers at JRZ, it's what they recommended.

[M4 CSL]

I will tell you a funny storey.

After installing the Dinan toe link kit, I loved the car. No extra noise. Everything was great.

Now the full suspension is in, I decided on taking another quick run. I was very careful at first going over speed humps, as the car is a lot lower than stock.

But now I had cleared the ones in my building before, I drove a bit faster, and I heard this god awful noise from the rear of the car. I am thinking Oh Crap!

Is this the Dinan bars, but they were great prior to suspension, or is this 1,000 Lbs springs in the rear. What have I done, this noise did not sound good.

Then I am running a million scenario's through my head, and get to the one about, reverting back to stock. Then I think, Oh Crap, I never retrieved my stock suspension...............Then I start to THINK......Then I start to Laugh.

I pulled over and sure enough, the stock suspension is all neatly boxed up in the boot. When I hit the speed bump hard, the stock suspension went up in the air and came down with an aweful noise. I went home Removed the stock suspension from the boot, and the car is perfectly quiet and doesn't make any strange sounds anymore. I felt like an idiot.

[tomtang]

LOL! Too funny.

[tomtang]

Brought my M3 back to Laguna Sec after a few hundred miles of street driving for some real fun and testing of the revised/upgraded JRZ RS Two dampers. Read about my day, look at some cool pictures, watch an HD 360 degree video of a few sub 1:40 laps here: http://www.jrzsuspension.com/sub-140-club.html

Car just has:

JRZ RS Two Sport dampers
GLOC R18 and R12 pads
Challenge stainless steel brake lines
Fall Line rear toe link kit
Rays 18x10.5 +22 TE37RT wheels (square)
275/35/18 Nexen Nfera SUR4G 200utqg street tires (square)